These brief summaries of MIT research are drawn from several sources and are issued throughout the year. More information on any of these stories can be obtained by contacting Elizabeth Thomson at the MIT News Office. In some cases, photos may be available for news organizations.
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Smart Surfaces. MIT engineers and colleagues from the University of California report a unique design of a “smart surface” that can reversibly switch properties in response to an external stimulus. The work paves the way for systems that could release or absorb cells and chemicals from surfaces on demand. In the journal Science, the researchers describe an example of their new approach in which they engineered a surface that can change from water-attracting to water-repelling with the application of a weak electric field. Switch the electrical potential of that field from positive to negative and the surface reverts to its initial affinity for water. “This opens the door to a variety of applications, including novel drug-delivery systems and smart templates for the bioseparation of one molecule from another,” said Robert Langer, MIT’s Germeshausen Professor of Chemical and Biomedical Engineering and leader of the work. Langer has appointments in chemical engineering, the Harvard-MIT Division of Health Sciences and Technology and MIT’s Biological Engineering Division. This work was funded by the NSF; the U.S. Army Research Office, the NIH; the Fonds der Chemischen Industrie in Germany; and the Whitaker Foundation.
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Top Invention. While it may seem that cell phones, computers and other technology gadgets are Americans’ most coveted items, teens and adults agree that the toothbrush is the one invention they cannot live without. The 2003 Lemelson-MIT Invention Index, an annual survey of Americans’ perceptions about inventing and innovating, found that technologically advanced items significantly lag in importance behind the toothbrush, which was developed in the 15th century. When asked to select the invention they could not live without from among five choices—toothbrush, automobile, personal computer, cell phone and microwave—more than a third of teens (34 percent) and almost half of adults (42 percent) cited the toothbrush. The automobile ranked a close second, getting votes from 31 percent of teens and 37 percent of adults.
‘Dark’ Burst Captured. Scientists racing the clock snapped a photo of a gamma-ray burst event one minute after the explosion, capturing for the first time a particularly fast-fading type of “dark” burst, which comprises about half of all gamma-ray bursts. A gamma-ray burst announces the birth of a new black hole; it is the most powerful type of explosion known, second only to the Big Bang in total energy release. This latest finding may double the number of gamma-ray bursts available for study and rattle a few theories as well, said scientists from MIT, based on an X-ray image taken by the MIT-built High Energy Transient Explorer (HETE) satellite, the first satellite dedicated to spotting gamma-ray bursts. These dark bursts are so named because they have had no detectable optical afterglow, until now. “Perhaps none of these bursts is truly dark, provided that we catch them fast enough,” said George Ricker, a senior research scientist at MIT’s Center for Space Research, who leads the international team that built and operates NASA’s HETE satellite.
Understanding Alzheimer’s. MIT physicists played a role in a Brigham and Women’s Hospital (BWH) study showing that brain damage related to Alzheimer's disease may start far earlier than previously thought and may be caused by newly implicated protein molecules. Physics research associate Aleksey Lomakin and George Benedek , the Alfred H. Caspary Professor of Physics, collaborated with senior author David Teplow of BWH on the study, which appeared Jan. 7 in the Proceedings of the National Academy of Sciences. Previous work has shown that the build-up in the brain of toxic proteins called amyloids leads to the emergence of Alzheimer's disease symptoms. Eliminating or lowering the levels of these proteins in the brain is the goal of potential treatments for the disease. Now BWH and MIT researchers believe that the memory loss associated with the disease begins long before protein deposits collect in the brain. “Until now, we knew these proteins were toxic, but we had little understanding of how they formed toxic structures,” Teplow said. “Our new studies show that in the most damaging form of Alzheimer’s disease, amyloid protein sticks together in a very distinct way, producing structures that enhance toxicity.”
Discarded Data. Discarded computers, even those with “erased” disk drives, may harbor confidential information such as credit card numbers and medical records, two MIT graduate students found. Scavenging through the data inadvertently left on 158 used disk drives, the students at MIT’s Laboratory for Computer Science found more than 5,000 credit card numbers, detailed personal and corporate financial records, numerous medical records, gigabytes of personal e-mail and pornography. The disk drives were purchased for less than $1,000 from eBay and other sources of used computer hardware. Only 12 were properly sanitized. “There are many stories in which somebody has bought a used computer and found confidential information on it, but nobody has ever quantified the scale of the problem,” said Simson Garfinkel, one of the students. “So we decided to find out.” Results from the study, which Garfinkel performed with Abhi Shelat, were published in the January/February 2003 issue of IEEE Security and Privacy. The research suggests that the secondary market is awash with confidential information, although work needs to be done to get more accurate statistics. More than 150 million disk drives were retired from primary service in 2002.
What’s in a Name? Tamika and Brendan had identical backgrounds and credentials. Yet when their resumes were submitted in response to help wanted ads in Boston and Chicago, many more prospective employers were interested in Brendan. Tamika and Brendan were two names selected by researchers at MIT and the University of Chicago School of Business to test whether applicants with black-sounding names received a fair shake when applying for a job. The answer: No! After submitting 5,000 resumes to 1,250 advertisers seeking administrative and sales help, researchers in both cities found that Brendan, Gregg, Emily and Anne received 50 percent more responses across the board than Tamika, Aisha, Rasheed and Tyrone. Family names used for white applicants were Baker, Kelly, McCarthy, Murphy, Murray, O’Brien, Ryan, Sullivan and Walsh. The African-American family names were Jackson, Jones, Robinson, Washington and Williams. The “white” applicants received one response—a call, letter or e–mail—for every 10 resumes mailed, while African-Americans with equal credentials received one response for every 15 resumes. “There was as much discrimination for the cashier-type jobs as there was for jobs like assistant to the president,” Professor Sendhil Mullainathan, an associate professor of economics at MIT, told WBUR on Martin Luther King Day.
Cosmic Reality Show. The longest X-ray look yet at the supermassive black hole at the Milky Way’s center has given astronomers unprecedented access to its life and times. The new data from NASA’s Chandra X-ray Observatory reveals that our galaxy’s central black hole is a temperamental actor, prone to frequent outbursts and occasional large explosions. The observations of the black hole, a.k.a. Sagittarius A* or Sgr A*, occurred over a two-week period for a total exposure time of 164 hours. During this time Sgr A* flared up in X-ray intensity half a dozen or more times. Astronomers also found evidence that suggests it had an even more boisterous past. These discoveries will help to unlock the secrets of how Sgr A* grows and how it interacts with its environment. “We are getting a look at the everyday life of a supermassive black hole like never before,” said Frederick Baganoff, a research scientist at MIT’s Center for Space Research, who presented these new results on behalf of an international team at a press conference last month at the American Astronomical Society meeting in Seattle. “We see it flaring on an almost daily basis.”
Schematic
showing the creation of MIT's "smart surface." Steps include
creating a field of molecules topped with "hats" (top), then
removing the hats so the molecules stand at a precise distance from each
other (middle). When a positive electrical potential is applied, the water-loving
tops bend down. The loops now exposed are water-repelling (bottom). Reverse
the electrical potential and the molecules straighten to their full height,
the tops once more attracting water (middle). Adapted from a figure
by Lahann et al. in the 1/17/03 issue of Science.